A system and method for optical spectroscopic measurements is described. A method for conducting a hairstyling business is also disclosed. A friction ring is retained in the channel. Control over this combination of variables determines a number of the characteristics of a filmcoating or multi-layered filmcoating formed using the method. The electrode feed lines and are connected to a feed line at least at one feed point on the electrode holder. The first major face comprises a material having coefficients of reflection and transmission that vary with the angle at which light is incident on the material.